Method of making stereoscopic film



jan. 2L E930. H. K. FAIRALL METHOD OF' MAKING STEREOSCOPIC FILM :Filed Deo. 22. 1925 and HRRY E. FA'IRALL, OF LOS MTGELES, CALIFORN-IA, ASSIGNOR TQ BNC'ULQ STEREO- SCOPIC FILM COMPANY, OF LOS ANGELES, CALFORNIA, A COBFORiATION O`CL1'- ronnie METHOD OF 'MAKING- STEREOSCOEIC Filiali):v

Application filed December 22, 1925. Serial No. 76,269.

An objectdof my invention is to provide a method of producing a stereoscopic iilm in which the right-hand image and the left-handA image are reversed, so that the right-hand image is on the left of the left-hand image and the left-hand image is on the right of the right-hand image, in order that they may be projected in this relationship on a screen'.

' vide a novel method of producing ina single lm, two layers of emulsion, one containing the right-hand and the other the left-hand image, this being accomplished by providing a celluloid hase and a gelatin emulsion containing the right-hand image and dyeing it one colon-'and a similar film containing the left-hand image and dyeing it another color and then combiningy the two into a single Aurther obj ect of the invention is to provideanovel method of malnng a stereoscopic. lmfcomposed oftwo film strips which are' made from half thickness stock so thatthe stereoscopic film will be of normal thickness; o A. still further object of my invention is to provide anovel method of printing the rightand left-hand series of images upon separate iilms so that the films can beseparately dyed and then cemented to form va singlefstereoscopic film. t.

- Another object ot the invention is to provide a novel method which includes the step of'simultaneously branding the diapositive films so that the positive films formed'from these will bebranded in such a mannerthat b `an observation ofthe lbrands in conjunc-v tion with'the action of. the photographs, the

two positive films can lbe matched together with absolute accuracy and a perfect stereoscopic Elm thus produced.

A further object of my -invention is to provide a novel method of forming a multiimage film which includesperiodical brand- 4ing and matching steps and includinggiving different colors to the secondary `ilms prior to their being united. ,Y

- Another object of my invention is to provide a method ,of forming corresponding diapositives and the nal step of pointing positives and uniting these in a single film.

' Other objects and advantages .of the invention will be made evident hereinafter.

Referring to the drawings in which I illustrate my invention,

Fig. 1 is a view of a primary negative having a right hand stereoscopic image thereon. j Fig. 2 is a secondary negative having a left hand stereoscopic image thereon.

F ig. 3 is a view of; a positive primary lilm` strip having a right'hand stereoscopic image thereon.

Fig. 4 is a secondary positive film strip having a left hand sterescopic image thereon. Fig. 5 is a section of the primary film strip shown in Fig. 3.'

Fig. 6 is a section of the secondary lilm c strip shown inFig. 4.

lFig. 7 is a section showing the primary and secondary ilm strips secured together.

Fig. 8 is the front View of the primary and secondary lm strips after they have been secured together.

v Fig. 9 is a View of the .glasses employed in viewing the stereoscopic picture on a screen.

Referring to the drawings and particularly to `Figs. 1 and A2, 11 indicates a primary 'negativeiilm and 12 indicates a secondary negative iilm.- The primary negative film 11 has a right hand stereoscopic image 14 fixed thereon, and the secondary negative film 12 has a left hand stereoscopic image 15 flxed thereon. The negatives 11 andv 12 may beA simultaneously exposed 1n a camera similar to thevone shown and described in my application entitled Binocular nonstop motion picturecamera, filed Nov. 21,1925, Serial No.

70,489. The frames of' these two negatives I .regular intervals on each film.

11 and 12 being exposed at the'same instant, the right hand and left hand stereoscopic images 14 andy 15 are therefore produced at the same time and they constitute views of the same object taken at diierent view-points so that they are in reality stereoscopic images when compared'with each other. The'right and left hand images 14e and lcorrespond to the images of any object which would be seen by the left and right eyes. It should be noted that the lms 11 and 12 are arranged so Referring tolFigs. 3 and 4, apositive primary 20 is made from the negative primary v 11 and a positive secondary21 is made from .35 that when they are securedtogether, as shown the negative secondary 12. The primary 20- as shown in Fig. 5 consists of a base 22 which is made of celluloidand an emulsion coating 23. The secondary 21 consists of a base 24`l made of Celluloid and an Yemulsion coating 25. If desired, the celluloid bases of the primary and secondary 20 and 21 may be conveniently made from half thickness stock so in Fig. 7 and Fig. 8, they will provide a stereoscopic film which is of standard thick; ness and therefore may be used in an ordinary projecting machine, not requiring any special projecting apparatus.`

Each frame of the primary 20 has a right hand stereoscopic image 28 lixed thereon and each frame of the secondary has a left hand stereoscopic image 29 fixed thereon. In order that the right and left hand stereoscopic images 28 and 29 will properly match when the two film strips are secured together back to back, it is necessary to have one of the images printed in reverse position. In the drawings I have shown the'let hand stereosc'opic image 29 reversed. By reversed is meant that the image 29 is printed through the celluloid base 24 ofthe secondary filml strip so that when the primary and secondary film strips are cemented together they will be in the intended stereoscopic relationship,v and when -they are viewed through proper glasses as shown in Fig, 9 a true stereoscopic picture will be seen.

After the primary and secondary lm strips have been exposedand'developed, and the imagesixed thereon, as shown in Figs. 3 and 4, they are cemented together as shown in Fig. 7 Before the strips are cemented tof gether, however, may. be desirable to dye the images, the images of one strip being dyed fore the primary and secondary lm strips are secured together. If desired, the images may be dyedafter -the strips have been cemented together, this being possible by a otation process. It should be understood that onl the images are dyed. If the whole of the rames were colored, the orange and blue colors would be superimposed on the film and they would prevent any light from passing through' the l'ilm onto the screen. By coloring only the images, it is possible to cast two images, one orange and the other blue, upon the screen. The primary lilm strip 20 has a `printed spot 32 on one edge thereof, and the secondary iilm strip has a-printed.

spot 33 on one edge thereof, at intervals of one foot or more.l Owing'to the fact that a great deal of clipping is necessary in the produc'tion of positivemo'tion picture films, it is extremely. important in the production of a stereoscopic film formed of two separately printed positives that a means be provided whereby the\A frames in these two positives which correspond in time of, exposure be superimposed relativeY to each other.y The uniting of the primary and secondary positive films so that corresponding frames are thus superimposed is practicably possible only by using the method of my invention which involves observation of theraction of,`

the frames of the films in connection with the positions of the images 32 and 33 of the black spots 16 and 17 printed onthese films.

It is to be noted that the need for clipping l out and then uniting corresponding ortions of two individual positive films, whlch must be secured to ether face to face to form a single positive lm, gives the spots 32 and 33 a utility in my process which is impossible in the finishing of apositive where this com-' prises only a single film. When the two strips are cemented together tle spots 32 and 33 are aligned and it is therefore certain .that

the two images which are taken at the same time will be shown on the screen at the same time. This marking of the films is necessary, as while it is very easy to matchthe action within a foot, an exact match by mere comparison of action is very diilicult. An absolutely perfect matching of the two. films is necessary as the eye resents any imperfection therein.

iger-,ase @i When the primary and the secondary film strips have been secured together, the celluloid bases 22 and 2li form substantially a single homogeneous base which, since the two bases 22 and 2a are half size, form a resulting lase which is oit the thickness or" an ordinary The right hand and left hand stereoscopic images 28 and 29 occupy positions as shown in Fig. 8 on the stereoscopic film. lt should be noted in this ligure that the right hand image 28 is on the left ot the lett hand image 29 and the left hand image 29 is therefore on the right of the right hand image 28. Although superior results are obtained by this arrangement otl images and such arrangement is highly desirable, it is not absolutely necessary and if desired the right and Alett hand images may be placed so that they are on the right and lett hand sides of each other, respectively. The primary and secondary images are projected on a screen by means of a standard projector and are viewed by a spectator through glasses 36 having a lett lens 37 which is blue and a right lens 38 which is orange. Therefore, the spectator sees the orange image with his lett eye and the blue image with his right eye, each eye seeing a dierent image.

lt will be understood then that the right eye sees the right image 28 through the orange eye-piece 38, and the left eye sees the left image` 29 through the blue eye-piece 37. 'lhe lines of vision 40, indicated between Figs. 8 and 9 of the drawings, cross at a point al. As previously pointed out, this crossing of the lines 'ot vision of the two eyesv greatly assists in bringing together and ifocus- -ing the right and left hand images so that better results are obtained. rlhis arrangement gives a resulting stereoscopic e'ect which is just the same as though the spectator saw the object tselfin place ot the right and left hand images von the screen.

lt will be noted that my invention includes the conception of producing complementary colored ositives which are combined into a single m containing both the right hand andthe left hand images. rlhe production oie the negatives is facilitated by the use of my novel camera which not only exposes the right and lett hand negatives simultaneously, butalso marks them simultaneously at distances of one foot or more to facilitate matching the action positively. 'llhe developing and further treatment of the negatives require no special apparatus or processes. The

i' production of the black and white positives Jfrom the negatives and the coloring of these positives also involve yno specialapparatus or knowledge except that one oi` the positives must be printed in reverse position through the Celluloid. The' cementing oi' the two positives together, back to back, is also a simj ple technical process. The resulting stereo- `substantiall scopic iihn is of standard thickness and may be projected from a standard projector by any operator without special instruction. lt will therefore be seen that by my invention, using means well known in the art, l have produced a simple and practical means ier making stereoscopic pictures available in any theatre, a result long sought but never before accomplished.

claim as my invention:

l. A method of forming a multi-image mo tion picture iilm which comprises: taking a plurality of series of individual negative photographs of the same action on continuous films, one for each series, corresponding photographs of said series being taken substantially simultaneously; periodically niark-V ing said lms while said photographs are being taken, to identity corresponding photographs oi' different series; printing positive photographs from said iilms onA secondary ilms, matching said positive photographs by observation or" the action on the photographs in. connection with the positions o? the prints of said marks on said secondary tilms so that corresponding photographs are opposite each other; and uniting said secondary iilms face to face when said positive photographs are so matched.

2. i method as in claim l in which s aid secondary films are given dierent colors prior to their being united.

3. A method of forming stereoscopic motion picture films which comprises: taking a plurality of series ota individual negative photographs of the same action on continuouslms, corresponding photographs orn said series being taken from diderent positions simultaneously; periodically `marking said iilms while said photographs are being takemto identify corresponding photographs ot diiierent series clipping said films; and matching and uniting clipped portions of said lms by an ins ection of said photographs in connection with said marl-:s so that the photographs corresponding in position on said lms correspond in time ci exposure. f

4. A method of forming' stereoscopic motion picture films which comprises: taking a plurality of series oiE individual negative photographs ot the same action on continuous films, correspondingphotographs of said series being taken from dii'erent positions substantially simultaneously; periodically marking said films while said 4photographs are being taken, to identify corresponding photographs of di'erent series; clipping said lms; matching and uniting clipped portions of said films by an inspection of said photographs in connection with said marks so that the photographs'corresponding in position on said nlms correspond in time of exposure; printing positive 'photographs from said lzns on secondary lms; matching said secondary iilms by observationof said positive photographs in'connection with the positions of the prints of said brands on said secondary ilm so that corresponding photographs are opposite each other; and uniting said secondary films face to face when so matched. 4

' 5. A method as in claim 4 in which said secondary films are given different lcolors *lo prior to their being united. v

En testimony whereof, I have hereunto set my hand at LosAngeles, California, this 17th day ofiDecelnb'e,n 1925. y 1 RY K. FMRALL. 

